‘Sion, Kurla most polluted in city in 2019’

Average annual concentration for particulate matter (PM) was highest across isolated pockets in the western and central suburbs of the city in 2019, revealed a report

Average annual concentration for particulate matter (PM) was highest across isolated pockets in the western and central suburbs of the city in 2019, revealed a report by city-based air quality research group UrbanSciences, which analysed the Central Pollution Control Board’s (CPCB) data for PM concentration in Mumbai, in 2019.

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CPCB has 10 stations across Mumbai where PM data is collected. In 2019, Mumbai’s annual average concentration for PM10 was 95 microgrammes per cubic metre (µg/m3) against the annual safe limit of 60 µg/m3; while PM2.5 last year was at 32 µg/m3 against the safe limit of 40 µg/m3.

“The yearly data from Mumbai shows that urban background PM concentration in winter in almost all neighbourhoods is a cause for concern,” said Ronak Sutaria, founder and director, UrbanSciences. He added,“More spatially dense air quality monitoring is needed.”

Monthly averages saw the highest PM10 (solid and liquid particles less than 10 microns, suspended in the air) concentration in Mumbai in January 2019 (195 µg/m3).

In terms of PM2.5 (particulate matter of the size 2.5 microns that can easily enter the lungs and cause health ailments) concentration, the levels were highest in December 2019 (80.4 µg/m3). However, monthly averages for PM2.5 from May to September 2019 were at a record low, below 15 µg/m3.

Location-wise data showed Sion was the most polluted in terms of PM2.5 concentration (44.2 µg/m3). Kurla reported the highest PM10 concentration (112.8 µg/m3). Borivli had the cleanest air, with lowest concentrations of both PM10 (47.5 µg/m3) and PM2.5 (24.1 µg/m3). “High vehicular congestion and biomass burning are major sources for Sion and Kurla while the presence of the national park in Borivli contributes to cleaner air quality,” said Sutaria.

Although overall PM concentrations were the lowest in over a decade owing to extended monsoon rainfall and tropical cyclones in the Arabian Sea, researchers warned that the data was not comprehensive. “It is important to understand the significance of regulatory grade monitoring, which is to primarily know the urban background levels. However, the exposure levels are missing. Kurla and Powai are showing monthly levels of 15 and 10 µg/m3 from May to September. These levels are not indicative of what people in those areas are breathing or exposed to,” said Sutaria.

Maharashtra Pollution Control Board (MPCB) said their assessment was also underway. “The impact of weather factors was surely there in 2019 combined with citizen awareness and efforts from various state agencies to address air pollution. However, there are some hotspots in the city that do not get captured easily in the current air monitoring network. With our action plan under implementation, significant change is expected over the next two to three years,” said chairman Sudhir Srivastava.